Gyro and Accel

Defining these values will override any defaults that most IMUs already have (see table at top for which drivers provide defaults that work unless you want to change the cofiguration).See the ImuCalibration page for the actual calibration instructions.

Defining the orientation of the IMU

Paparazzi has parameters to define the orientation of the IMU with respect to the body of the vehicle.

Important Not all algorithms properly deal with any BODY_TO_IMU orientation. See the notes for the respective implementation at Subsystem/ahrs and the issue on github.
For the algorithms not supporting that, the only way to properly deal with 90deg rotations is to just change the sensors channels (e.g. so that what are normally the x-axis gyros and accels become the y-axis sensors, etc.)

Ignore 'on the ground' resting values as depicted in the above image. They will change once the vehicle is in flight. The aim is to get the 'in flight' values of "int32 body_phi" & "int32 body_theta" as close to zero as possible.